POS0501 SEQUENTIAL ULTRASOUND IN ARTHRALGIA PATIENTS AT RISK FOR INFLAMMATORY ARTHRITIS; IS IT HELPFUL FOR RISK STRATIFICATION IN DAILY PRACTICE?
Authors: C. Rogier, M. Kortekaas, A. Van der Helm-van Mil, P. De Jong, E. Van Mulligen
Journal: Annals of the Rheumatic Diseases (2022)

Background Musculoskeletal Ultrasound (MSUS) is often used to assess the presence of subclinical joint inflammation in patients presenting with arthralgia suspicious for progression to inflammatory arthritis (IA). Even though evidence-based guidelines for these patients are still absent, presence or absence of subclinical joint inflammation often influences management decisions in daily clinical practice. Studies so far focused on MSUS results at presentation with arthralgia. However, it is unknown if and how MSUS results change over time, and whether repeating MSUS is helpful in demonstrating or ruling out impending RA with greater certainty. Objectives To investigate whether sequential imaging at 4-months, in addition to baseline evaluation, is helpful in the risk stratification of arthralgia-patients. Methods Arthralgia-patients suspicious for progression to IA were included in the Rotterdam clinically suspect arthralgia cohort. At baseline and at 4-months a bilateral MSUS-examination was performed of the joints and tendons in both hands and feet. Subclinical inflammation was defined as GS&gt;1 and/or PD&gt;0, this was scored according to the latest OMERACT- guidelines.(1, 2) Based on a large US study carried out in a symptom-free population, the cut-off value in MTP 2-3 was considered present if GS ≥3 and/or PD ≥1.(3) Patients were followed for one-year on development of IA, identified with joint examination by experienced rheumatologists. The value of MSUS was studied separately for patients with and without subclinical joint inflammation at baseline. In a sensitivity analysis, ACPA-stratification was applied. Results A total of 52 consecutive patients were studied; 29% developed IA after one year. At baseline, 25 patients had subclinical inflammation and 27 patients did not have subclinical inflammation. In these groups respectively 28% and 7% developed IA before the 4-month-visit and therefore did not have repeated MSUS (Figure 1 A/B). In the patients with a positive MSUS at baseline, 28% had a negative MSUS at four months, all these patients did not progress to IA, irrespective of tender joints count(Figure 1A). In the group of patients with a negative MSUS at baseline, 26% achieved a positive MSUS at 4-months. All patients with a negative MSUS at baseline and no tender joints at 4-months did not progress to IA, regardless of the MSUS results. Patients with a negative MSUS at baseline and tender joints at 4-months developed IA infrequently, without relevant differences between those that did or did not develop a positive MSUS at 4-monthts. Overall, only a minority of patients whose MSUS progressed from negative to positive indeed developed IA, whereas this repeated MSUS was falsely positive in most cases(Figure 1B). Despite the small numbers, ACPA-stratification was performed, this showed a similar trend. Figure 1. Sequential ultrasound at baseline and after 4-months of follow-up in arthralgia-patients at risk for inflammatory arthritis with subclinical inflammation at baseline (A) and without subclinical inflammation at baseline(B). Conclusion Within arthralgia patients with a positive MSUS at baseline, a negative MSUS after 4-months may be an incentive to exclude arthralgia-patients from further follow-up. Within the patients with a negative MSUS at baseline, repeating MSUS may induce more false positive than correct positive results. References [1]D’Agostino MA, Terslev L, Aegerter P et al. Scoring ultrasound synovitis in rheumatoid arthritis: a EULAR-OMERACT ultrasound taskforce-Part 1: definition and development of a standardised, consensus-based scoring system. RMD Open. 2017;3(1):e000428. [2]Naredo E, D’Agostino MA, Wakefield RJ et al. Reliability of a consensus-based ultrasound score for tenosynovitis in rheumatoid arthritis. Ann Rheum Dis. 2013;72(8):1328-34. [3]Padovano I, Costantino F, Breban M et al. Prevalence of ultrasound synovial inflammatory findings in healthy subjects. Ann Rheum Dis. 2016;75(10):1819-23. Disclosure of Interests None declared.